Control apparatus



March 18, 1930. Y WALTEMATH 1,751,374

CONTROL APPARATUS Filed Oct. 9, 1926 Inventor: Adolf A/altema'th,

His Attormey Patented Mar. 18, 1930 UNITED STATES PATENT OFFICE ADOLFWALTEMATH, OF OBEBSCEONEWEIDE, GERMANY, ASSIGNOR TO GENERAL ELEC- TRIOCOMPANY, A CORPORATION OF NEW YORK CONTROL APPARATUS Application filedOctober 9, 1926, Serial No. 140,667, and in Germany September 3, 1925.

duce a predetermined time delay between different switching operations.

It is known that a certain time interval 1s 10 required for the plate oranode current of an electron discharge device to reach a predeterminedvalue after current is first su plied to the cathode heating circuit ofthe evice. The duration of this time interval is dependcut on severalfactors such as the cathode construction, the materials of which thecathode so from the following description when considered in connectionwith the accompanying drawings and its scope will be pointed out in Ythe appended claims.

Referring to the drawing, the single figure thereof shows a controlapparatus wherein my invention has been embodied.

The figure shows a switch 1 comprising a movable contact 2 which isbiased to its closed position and is provided with an operating coil 3supplied with current through suitable means shown as supply leads 4. Anelectron discharge device 5 comprising an anode 6 and a cathode 7 isprovided for producing a predetermined time delay between operation ofthe switch 1 and a switch 8 which is connected in a circuit 9 and isprovided with a movable contact 10 and an operating coil 11. It will beobserved that the anode 6 and cathode 7 are connected through theoperating coil 11 to a source of current 12 and that heating current issupplied to the cathode 7 from a source 13 through an adjustable controldevice 14 and the switch 1.

With these connections, current is transmitted through the operatingcoil 11 and the 'switch 8 is maintained in its open position so long asthe operating coil 3 is deenergized. Upon energization of the coil 3,however, the cathode heating circuit of the device 5 is interrupted. Thetime interval between deenergization of the coil 3 and closure of theswitch 8 is dependent on such factors as the structure and compositionof the cathode and the voltages of the sources 12 and 13. It will beapparent that the cathode 7 may be an oxide cathode or any other type ofcathode suitable for producin the desired time delay between operation 0the switches 1 and 8, upon closure of the switch 1.

A switch 15 connected in the anode circuit of the device 5 is arrangedto be operated by the coil 3 which also operates the switch 1. Underthese conditions, the switch 8 is instantaneously decnergized uponenergization of the circuit 4 and is energized at a predetermined timeafter deenergization of this circuit. The switch 8 is thus closedinstantaneously and opened with a predetermined time delay.

The embodiments of the invention illustrated and described herein havebeen selected for the purpose of clearly setting forth the principlesinvolved. It will be apparent, however, that the invention issusceptible of being modified to meet the different conditionsencountered in its use and I therefore aim to cover by the appendedclaims all modifications within the true spirit and scope of myinvention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,-

1. The combination of a plurality of circuits, an electron dischargedevice comprising a cathode and an anode, means connected between saidcathode and anode for changing the connections of one of saidcircuits,aswitch operable upon energization and deeenergization ofanother of said circuits to open and close the heating circuit of saidcathode, and means arranged to interrupt the connection between saidcathode and anode only when said switch is opened.

2. The combination of an electrical circuit, an electron dischar edevice provided with anode and cathode eating circuits,electroresponsive means connected in said anode circuit for controllingthe connectionsof said electrical circuit, and means associated withsaid anode and cathode heating circuits for instantaneously deenergizingsaid electroresponsive means and for ener izing said electroresponsivemeans only a er a predetermined interval of time.

In witness whereof, I have hereunto set my hand this 17th day ofSeptember, 1926.

ADOLF WALTEMATH.

